Figure 64. Model capsule of 15-inch diameter with simplified polar penetration 

 closures: assembly. Note the single spring-loaded tie rod. 



Short-term tests were performed on 1 1 capsules (Table 4). All of the 

 models were equipped with tie rods except for capsules 0, 16 and 20. These 

 tests were to provide immediate data on the maximum hydrostatic pressure 

 the capsule can withstand under different temperatures in the 32 to 1 14°F 

 range. Furthermore, the critical pressures at which implosion of the models 

 occurred would serve as benchmarks to which critical pressures of models 

 tested under long term (Table 5) and cyclic (Table 6) conditions could be 

 compared to determine the effect of cycling, or long-term loading on their 

 structural integrity. For all of these tests, water was used on the exterior 

 and interior to insure proper temperature control. Since the water in the 

 interior of the hull was vented to the atmosphere by tubing, its presence 

 had no reinforcing effect on the hull. 



95 



